1. Field of the Invention
The present invention relates to multiferroic thin film materials, and more particularly relates to methods of preparing said materials.
2. Description of Related Art
The investigation of multiferroics has recently emerged as one of the most exciting frontiers in material science. Multiferroics are magnetoelectric elements and have potential applications in the design and synthesis of multifunctional materials due to coupling of their coexisting unusual electric and magnetic orderings. The magnetic polarization can be switched by applying an electric field, and the ferroelectric polarization can be switched by applying a magnetic field. As a consequence, multiferroics are important materials for the investigation of fundamental physics, as well as in the design of new device concepts. These compounds not only present opportunities for magnetic and ferroelectric devices, but also can serve as the basis for potential applications including modulated optical properties, magnetoelectric multiferroic resonators, phase shifters, delay lines and filters for advanced microwave and millimeter wave applications, detectors for field fluctuation and field monitoring, information storage, the emerging field of spintronics, and sensors.
The behaviors of magnetoelectric coupling in multiferroics are of prime significance. Among the many multiferroics, bismuth ferrite (BiFeO3) is known to be the only material that displays multiferroism at room temperature and has attracted considerable attention. Magnetoelectric coupling in BiFeO3 thin film has not previously been developed. Electrical control of magnetic domain structure in multiferroic BiFeO3 thin films at room temperature was first observed in 2006. However, ferroelectric polarization switched by a magnetic field has not previously been documented.
The use of multiferroic compounds, including BiFeO3, has previously been disclosed, as has different methods for synthesizing multiferroic thin films, such as, pulsed laser deposition (PLD), liquid-phase epitaxy, sol-gel methodology, and chemical solution deposition. However, all of the previously disclosed methods for synthesizing multiferroic thin films have required complicated, expensive procedures.